IN THIS ISSUE:
• A Caution on Colored Sunglasses for Color-Defective Patients
Many sunglass tints currently permitted for drivers reduce the ability of color-deficient patients to detect and recognize traffic signals. In general, combinations of signals and sunglasses of similar colors are of particular concern. The authors present guidelines for sunglass tints based on their findings and caution against relaxing current standards. (p. 296)
• Can Fenestrations Help With Hyperopic Orthokeratology?
The fact that central lens fenestrations did not affect refractive or corneal curvature changes in hyperopic orthokeratology (OK) suggests to the authors that corneal shape change in hyperopic OK may be due to direct lens molding mediated by hydraulic pressures generated in the post lens tear film, rather than from an apical suction force. (p. 306)
• Children Wearing Soft Contact Lenses Have No Elevated Resident Microbial Risk
The authors track microbial colonization of the ocular surface, at regular intervals over a 2-year period, in a group of children (aged 8–12 years) who wore soft CL. As in adults, the lids and conjunctiva were contaminated with predominantly Gram positive bacteria that are resident microbiota. There were no significant changes in the incidence or types of microorganisms isolated from the ocular surface during the 2-year lens wear. (p. 312)
• Do Contact Lens Wearers Improve Vision by Correction of Higher Order Aberrations?
Contact lens designers attempt to control spherical aberration in the eye/lens system by manipulating the radial variation of power within the optic zone. Each optical power profile design differs yet produces the same nominal power. Interestingly, these differences do not seem to create clinically significant vision consequences and the authors raise the question of whether there is any practical value to correcting higher order aberrations in the general population. (p. 318)
• Contact Lens-Induced Conjunctival Epithelial Flaps
In a recently reported phenomenon associated with contact lens wear, sheets of cells detach from the underlying conjunctiva, forming a conjunctival epithelial flap (CEF). About 35% of the authors’ 205 study patients developed CEF, almost always in the superior conjunctiva. Over 60% were bilateral. Survival statistical analysis showed a significantly greater risk of CEF with silicone hydrogel contact lens continuous wear compared with gas permeable lens wear. It is not yet known whether CEF poses any adverse health effects. (p. 324)
• Transmission Changes of Visible and UV Light in Worn Contact Lenses
Transmittance is modified after contact lenses wear, probably due to the formation of biofilms on the contact lens surface. The good news is that silicone-hydrogel and conventional hydrogel contact lens materials that provide UV protection (UV-blocker) maintain this property even after being worn and the changes observed in the visible spectrum does not seem to alter visual performance of silicone-hydrogel contact lenses. (p. 332)
• Documenting Corneal Swelling Reliably in Extended Wear of Contact Lenses
The authors induce corneal swelling with extended wear high (lotrafilcon A) and low (etafilcon) Dk contact lenses. They note that swelling across the central and peripheral cornea can be reliably noted with both Orbscan pachymetry and ultrasonography. (p. 340)
• Newer Silicone Hydrogel Lenses Perform Well
Ten years after the introduction of silicone hydrogel lenses they have become very popular for both daily and extended wear. Third generation lenses, which maintain high oxygen transmissibility despite also being higher in water content and lower in modulus, are just now becoming available to practitioners. This performance study of these newer lenses shows them to be a promising alternative to currently available lenses. (p. 350)
• Does Examiner Bias Affect Convergence Insufficiency Symptom Survey (CISS) Scores?
The authors claim “No.” In asserting this they suggest that the CISS survey is useful and valid in both clinical research and patient care of children. (p. 357)
• High Refractive Errors and Amblyopia in Children Entering School in Iran
The authors draw attention to the need to address what they consider to be a relatively high prevalence of refractive error and amblyopia in 6-year-old children entering school in Iran. (p. 364)
• A New Prototype for Measuring the Corneal Topography
The authors present a new prototype, based on the Hartmann test, for measuring the corneal topography. They argue that since the Hartmann-based topographer potentially eradicates the skew ray error, it can be an alternative to improve the corneal topography evaluation. (p. 370)
• Approximating Lens Power
The gulf between retinoscopy refractive data, and that measured with aberrometers, is largely due to the use of paraxial approximations. The spherical equivalent measure introduces nonconstant approximations, leading to a systematic bias. The author offers “a robust and clinically useful representation” of average lens power that includes spherical aberration, is not limited by paraxial approximations, and is not subject to the systematic bias that occurs with the spherical equivalent power. (p. 382)
• Diabetic Papillopathy Now Makes Sense
Diabetic papillopathy is generally a clinical diagnosis of exclusion for optic disc edema. This case report, along with reconciliation of clinical data in the literature review, substantiates the existence of diabetic papillopathy as a distinct clinical entity. From diabetic vasculopathy principles, the authors offer a relationship between diabetic papillopathy and optic nerve ischemia. (p. 395)
• A Simple Surgical Treatment for the Complications of Corneal Grafts?
Postoperative intraocular pressure (IOP) elevation is the most common complication to occur after penetrating keratoplasty (PKP). But IOP corrective surgery typically adversely affects the graft. Here the authors performed selective laser trabeculoplasty, a simply and easy surgical alternative to treat secondary glaucoma occurring after PKP, and found a great reduction in IOP, without graft complications. (p. 404)